Critical SCI systems
Critical SCI systems means any SCI systems of, or operated by or on behalf of, an SCI entity that:
(1) Directly support functionality relating to:
(i) Clearance and settlement systems of clearing agencies;
(ii) Openings, reopenings, and closings on the primary listing market;
(iii) Trading halts;
(iv) Initial public offerings;
(v) The provision of market data by a plan processor; or
(vi) Exclusively-listed securities; or
(2) Provide functionality to the securities markets for which the availability of alternatives is significantly limited or nonexistent and without which there would be a material impact on fair and orderly markets.